Method of treating the fabric for power-transmission belts.



E. L. BURRELL.

METHOD OF TREATING THE FABRIC FOR POWER TRANSMISSIQN BELTS.

APPLICATION HLED FEB.13| I915.

1,218,052. Patnted Mar. 6,1917.

%'lzzesses ERNEST L.v BURRELL, or onrcneo, ILLINOIS.

.Illrlttlill0]) OF TREATING THE FABRIC FOR POWER-TRANSMISSION BELTS;

Specification of Letterslatent.

Patented Mar. 6, 191 '7'.

Application filed February 13, 1915. Serial No. 7,946.

To all whom 'z't may concern;

Be it known that I, ERNEST L. BURRELL, a

citizen of the United States of America, and

- a resident of Chicago, county of Cook, and 5- State of Illinois, have invented certain new and useful Improvements in Methods of;

Treating the Fabric for Power-Transmission Belts, of which the following is a specification.

Cotton fabric specially woven and treated with various compositions, with a view to strengthening and preserving the fibers thereof, has long been used for power transmission purposes. The nature of the compositions used and the method of treating the fabric therewith have been varied and'numerous. -However, none of the belts so far produced has been suitable for use in many of the places where leather belts have heretoforebeen considered necessary, for the reason that the compositions used have either not materially increased the strength of the fibers, so as to render the material any morev suitable for use, or have not preserved the material against deterioration, or have actually caused a deterioration thereof.

The main object of this invention, therefore, is to provide an improved method of preparing cotton Wovenbelting material for use as power transmission belts, by treating the material with a new combination of in-- gredients which serve to strengthen and preserve the fibers of said material, and render the same impervious to and unaffected by moisture.

In the accompanying drawing the figure represents a fragment of woven cotton belting material of the kind most suitable for use in making power transmission belting, and with which the process hereinafter described is followed out. This is preferably a solid close-woven fabric woven with the desired number of layers to provide the necessary thickness. Thus, there are no stitches .to come apart and weaken the belt. However, laminated material could be used with equal effectiveness so far as the action of the ingredients used in following out the process is concerned.

Although perfectly ripe cotton fiber consists of almost pure cellulose, the cells are filled with a somewhat gelatinous matter which in the untreated fabric is subject to oxidization and decay. and in time tends to deteriorate the fiber. In the compounds and methods heretofore used in the treatment of woven cotton belting material, the attempt has been made to impregnate the fabric so as to isolate this foreign gelatinous'm'atter from the action of air-and moisture.

In my improved method of treating cotton woven belting material, the first step has been to neutralize this gelatinous matter by subjecting the material'to thea'ction of tannic acid in substantially the same manner as that pursued in the tanning of hides. When thus infused with tannic acid the gelatinous matter is converted into a tough .imputrescible substance, so that if it is there'- after exposed to air and moisture, it is unaffected. In addition,aconsiderable quantity of tannin is, absorbed by the fibers and are thereby preserved against deterioration. It has also been found that this treatment increases the tensile strength of the material about one-third. I

An auxiliary step in the tanning process is to set the tannin with a mordant, such as tartar emetic (antimony oxy tartrate) This is done by preparing a fixing bath-of about two hundred'pounds of water to which has been added about one-half per cent.-of tartar-emetic. About one hundred pounds of the fabric is then immersed in the bath long enough for the desired action to take place. This prevents the tannin from being freed from the fabric, as is otherwise likely to occur.

The next step is to impregnate the tanned fabric with a water-proofing compound which is caused to penetrate the entire fibrous structure. The ingredients that can be used for this purpose are many and varied. However, there are certain characteristics which I have found this compound should possem in orderto produce belting having the desired qualities. In the first place, the' compound should contain in- I gredients which .are capable of giving weight or body to the fabric and. which are unaffected by atmospheric changes, so that the treated material will not become either stiff or too pliable .when exposed to cold or heat. On the other hand,'the use of ingredients should be avoided, which of themselves are subject to deterioration and which, by reason thereof, are likely to affect the fabric. The compound that I have found to pos- 'sess these qualities is one made up of wax tailings, parafl'in, and lubricating oil, coming compound in order to increase its fricbined in. substantially the "following proportions:

Wax-tailings 900 lbs. Paraffin 260" Lubricating oil 200 These products are mixed in a tank andheated to a temperature of from 200 to 225 F. The fabric is run through the solu-.

ject to deterioration by the action of any of the ingredients, but in fact,'its preservation is increased. The lubricating oil is preferably a high grade cylinder oil, and is used primarily because it is not affected by the more usual low temperatures, and there is little danger of the belt losing its pliability in cold weather.

The fabric after being impregnated with this water-proofing compound presents an oily surface which will not afi'ord the best frictional contact with the pulleys. The final step. in this improved method, therefore, is to face the belt with a suitable dresstion on the pulley faces and lengthen its wearing qualities. The dressing must be of such a character that it will penetrate the oily surface of the fabric treated in above manner so as to permanently adhere thereto. The following compound has been found to produce very satisfactory results in this respect:

Water 200 Lbs. Dry shellac 24 'Dry borax 6 Dry asbestine powder 10 Dry pigment (green) 100 The dressing is prepared by adding the borax and shellac to water and bolling. After the shellac has been dissolved the asbestine powder and pigment are added and ever, has been found'to give the most satisfactory results.

The kind of pigment used is not vital so far as the action of the dressing is concerned, the color specified being used primarily for the purpose of making a distinctive appearance.

The water, shellac, and boraX constitute an adhesive for applying and retaining the asbestine powder and pigment upon the surface of the belt.

The dressing is applied by brushing it on the surface of the belt or by running the belt through a tank containing the solution, the solution being thoroughly stirred to keep the pigment from gravitating. The dressing penetrates a slight distance into the fabric and will dry quickly leaving a part of elastic filament over the surface of the belt which will not crack or peel off, and is not affected by atmospheric changes. This coating or filament is impervious-to water, oil, moisture, or any other substances that the belt may come in contact with, and prevents the same from reaching the fabric. However, the water-proofing compound tends to ooze out of the belt very slightly when the belt is running, but sufliciently to obtain a smooth wearing surface on the side of the belt next to the pulleys, so as to keep it in the best of condition.

It will be understood that the specific ingredients and other details of the process and product herein described, and the combination thereof may be modified by substitutions, omissions and additions without departing from the spirit of this invention as defined by the following claims.

I claim:

1. In the manufacture of power transmission belts from woven fiber belting material, the improved method of preparing the material which consists in subjecting it to the action of tannic acid, setting the tanninby means of a mordant, and then impregnating thesame with a water-proofing compound.

2. In the manufacture of power transmission'belts from woven fiber belting material, the improved method of preparing the material which consists in subjecting it to the action of tannic acid, setting the tannin by means of tartar emetic, and then impregnating the same with a water-proofing compound.

3. In the manufacture of power transmission belts from woven fiber belting material, the improved method of preparing the material which consists in subjecting it to the action of tannic acid and then impregnating the same with a heated water-proofing compound comprising substantially 66% waX tailings, 19% paraffin, and 15% lubricating oil.

4. In the manufacture of power transmission belts from'woven fiber belting material, the improved method of preparing the material'which consists in subjecting it to the action of tannic acid, impregnating the same with a'water-proofing compound and then facing it with an asbestine dressing.

5. In the manufacture of power transmission belts from woven fiber belting material,

the improved method. of preparing the material which consists in subjecting it to the action of tannic acid, impregnating the same with a water-proofing compound and then facing it with an asbestine dressing compound containing a pigment.

6. In the manufacture of power transmission belts from Woven fiber belting material, the improved method of preparing the material which consists in' subjecting it to the action of tannic acid, impregnating the same with a water-proofing compound and facing it with a shellac composition containing asbestine.-

7 In the manufacture of power transmission belts from woven fiber belting material, the improved method of preparing the material which consists in subjecting it to the action of tannic acid, impregnating the same with a water-proofing compound and facing it with a shellac composition containing as-' bestine and pigment.

8. In the manufacture of power transmission belts from woven fiber belting material, the improved method of preparing the material which consists in subjecting it to the action of tannic acid, impregnatlng the same with a water-proofing compound and facing it with a shellac composition containing substantially 10% shellac, 3% b'orax, and 87% water with which has been ,combined, in

substantiallyequal amounts by weight, a

mixture of asbestine and pigment in the proportions of approximately 1 to 10.

9. In the manufacture of power transmission belts from woven fiber belting material, the improved method of preparing the material which consists in subjecting it to the action of tannic acid, impregnating it with a heated water-proofing compound comprising paraffin and a high boiling mineral oil, and then facing the same with an asbestine dressing containing a pigment.

Signed at Chicago this 5th day of Feb ruary, 1915.

v ERNEST L. BURRELL.

Witnesses:

EDWIN PHELPS, C. M. FEIGEL. 

